In hair ornament product s such as hairpieces, hair wigs, crepe hair, hair bands, and doll hair, conventionally, human hair is mainly used. However, in recent years, it is becoming difficult to obtain human hair, and human hair is being replaced with fibers for artificial hair using synthetic fibers, such as acrylic-based fibers (e.g., modacrylic fibers), polyvinyl chloride-based fibers, and polyester-based fibers. In particular, polyester-based fibers have high gloss on the fiber surface thereof. Thus, when polyester-based fibers for hair ornament products, particularly for hair products attached to human hair such as hair wigs and hairpieces, are used, the hair overall looks unnatural due to the difference in gloss between the fibers and the human hair.
Thus, various processes for improving the gloss of polyester-based fibers have been investigated. For example, as a process for adjusting gloss, Patent Document 1 proposes a technique for adjusting fiber gloss by incorporating organic particles or inorganic particles into a polyester-based fiber for artificial hair. This is a technique for forming protrusions on a fiber surface using fine particles. In order to form very small recesses on the surface of a fiber for artificial hair, alkali reducing treatment has to be performed, and the processing steps become complex and costs increase. Furthermore, depending on the amount of organic particles or inorganic particles added, the color development property (hue) deteriorates, and the tactile feel is rough and vastly different from that of human hair, and thus a polyester-based fiber for artificial hair having gloss and a tactile feel close to that of human hair has not been obtained.
Furthermore, Patent Document 2 discloses a technique for suppressing gloss by adding an acidic phosphorus-based compound. It is stated that the addition of the acidic phosphorus-based compound reduces the viscosity of a polyester resin and, at the same time, reduces the dispersibility of a brominated epoxy-based flame retardant blended therewith, so that projections are formed on the fiber surface layer to reduce the gloss. Patent Document 3 discloses a technique for suppressing gloss, using antimony oxide. It is stated that this process allows a reaction of a brominated epoxy-based flame retardant to occur due to the presence of antimony oxide, to form agglomerates having a certain size, so that projections are formed on the fiber surface layer as in Patent Document 2. However, in the case of the technique described in Patent Document 2, an acidic phosphorus-based compound is likely to absorb moisture, and thus the gloss suppressing effect may become unstable. Furthermore, in the case of the technique described in Patent Document 3, yarns break when spun for a long period of time because antimony oxide is used.
Meanwhile, fibers for artificial hair are required to have high flame retardance. Patent Document 4 describes a flame retardant polyester-based artificial hair containing a bromine-containing flame retardant, an antimony compound, and a phosphite-based compound. Patent Document 5 describes a flame retardant polyester-based artificial hair containing a bromine-containing flame retardant, an antimony compound, and a heat-stabilizer such as a phosphite compound. Patent Document 6 describes a flame retardant polyester-based artificial hair containing a brominated epoxy-based flame retardant and a reaction accelerator such as a phosphite compound. However, in Patent Documents 4 to 6, gloss is not mentioned.